[dahy-uh-tuh m, -tom]
- any of numerous microscopic, unicellular, marine or freshwater algae of the phylum Chrysophyta, having cell walls containing silica.
Origin of diatom
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for diatom
In fact, the two pass without any sharp boundary into each other, and both present transitions to the Diatom ooze.
The diatom itself may be washed in the same way, if it is not too small.The Diatomaceae of Philadelphia and Vicinity
Charles Sumner Boyer
This diatom is often found in abundance in the water supplies of cities.
The little things, he continued, delicately perforating the atmosphere as though selecting a diatom.Iole
Robert W. Chambers
He turns himself outside in, and makes a temporary stomach, and proceeds to digest the soft parts of the diatom.
- any microscopic unicellular alga of the phylum Bacillariophyta, occurring in marine or fresh water singly or in colonies, each cell having a cell wall made of two halves and impregnated with silicaSee also diatomite
C19: from New Latin Diatoma (genus name), from Greek diatomos cut in two, from diatemnein to cut through, from dia- + temnein to cut
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for diatom
Online Etymology Dictionary, © 2010 Douglas Harper
- Any of various one-celled aquatic organisms of the class Bacillariophyceae that have hard bivalve shells (called frustules) composed mostly of silica, can perform photosynthesis, and often live in colonies. They make up a large portion of the marine plankton and are an important food source for many aquatic animals. The skeletal remains of diatoms are the main constituent of diatomite.
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